1. Field of the Invention
The present invention generally relates to semiconductor substrate processing systems. More specifically, the invention relates to an apparatus for supporting a substrate in a semiconductor substrate processing system.
2. Description of the Related Art
Accurate reproducibility of substrate processing is an important factor when increasing productivity for integrated circuit fabrication processes. Precise control of various process parameters is required for achieving consistent results across a substrate, as well as results that are reproducible from substrate to substrate. More particularly, uniformity of the substrate temperature during processing is one requirement for achieving accurate reproducibility. During substrate processing, changes in the temperature and temperature gradients across the substrate are detrimental to material deposition, etch rate, step coverage, feature taper angles, and the like.
Generally, during processing, the substrate is disposed on a substrate support (e.g., electrostatic chuck, susceptor, and the like) that is thermally coupled to a heat source, such as an embedded heater, e.g., a resistive heater and the like. Additionally, in some applications, heat is also produced by the process itself (e.g., plasma process). To enhance the processing and minimize undesirable yield losses, it is essential to control the temperature as well as the temperature uniformity of the substrate.
Therefore, there is a need in the art for a substrate support having means to control the temperature as well as the temperature uniformity of the substrate.